Im studying hard to find information about the ic and i can find any
information about it;( But after i take a small look into the
service manual of the tr-505 i found a good replacement!Tc531000p!!!
I got the pin out of this chip so we can change by any other popular
eprom on the market.The tr-707 include inside a converter that
change bites into ANALOG. So no worry about that. the only problem
still, what is the language (hex,bin,etc..) I have to make a copy of
the rom before attempting something And study the language. But if
this is possible, and im quite sure it is, a new life will begin for
the tr series. Will see.Hope my works going to get fruits

bizz
Montreal,québec


--- In tr-707@yahoogroups.com , "foleymachine" <foleymachine@y...>
wrote:

> just a guess, but is there some kind of device that reads chips

and

> converts it automatically you might have to find some way to read
> the chip and then reconfigure the bits into a pcm sound. i don't

know.

>
> --- In tr-707@yahoogroups.com , "bisaillon3" <bisaillon3@y...>

wrote:

> > Ok, i make my search and i found a pretty chip eprom programmer

u

> > can build yourself. This is the
> > link . http://home.quicknet.com.au/andrewm/eprom1/
> >
> > Now i have to figured out how to convert a sound into binaries

and

> > find something about the clock input in the chip. Any advice
> >
> > tks
> > bizz
> >
> >
> >
> > --- In tr-707@yahoogroups.com , "foleymachine"

<foleymachine@y...>

> > wrote:
> > > not really anything substantive on AH.
> > >
> > > another thing i thought of is swapping the cymbal roms with

one

> of
> > > the other ones. i don't know if this would be interesting
> > scrambled
> > > up garbage or just various shorter versions of the cymbals.

i'll

> > > definitely try it when i get further into the rom switching
> > project.
> > >
> > >
> > > --- In tr-707@yahoogroups.com , "foleymachine"

<foleymachine@y...>

> > > wrote:
> > > > bizz,
> > > > yeah, that sounds super good! i don't know anything about
> eproms
> > > but
> > > > i definitely want to research it and see what i can find. i
> > think
> > > > i've seen it mentioned on AH, i'll check the archives.
> > > > greg
> > > >
> > > >
> > > > --- In tr-707@yahoogroups.com , "bisaillon3"

<bisaillon3@y...>

> > wrote:
> > > > > hey greg!!!
> > > > > Thats is good idea!!! U have to send me some

pick

> > of
> > > > your
> > > > > bend. For the m64-c cartridge i got some news... Roland

will

> > send
> > > > me
> > > > > the schematic of the cartridge. So we can figured out to
> > upgrade
> > > > > this thing!!! It will be post shortly may be in the middle

of

> > > this
> > > > > week.
> > > > >
> > > > > For your upgrade of the chip 707/727 thats a pretty good

idea

> > and
> > > > > pretty simple to do. I think of that, and why we not

burning

> a
> > > new
> > > > > sound on the rom Imagine!!! I look at some epprom burner

to

> > do
> > > > this
> > > > > but im not a expert in that. the only thing we have to

figure

> > is
> > > to
> > > > > find a epprom like the 707(8 bit)i think! That will be
> heaven!
> > If
> > > > we
> > > > > can create a box with a serial printer connector and

change

> > each
> > > > > time u want the sound of 707!!!
> > > > >
> > > > > So any expert in rom The part number of the ic is
> HN51256pc71.
> > > > >
> > > > > regards
> > > > > bizz
> > > > >
> > > > >
> > > > >
> > > > > --- In tr-707@yahoogroups.com , gregory zifcak
> > <foleymachine@y...>
> > > > > wrote:
> > > > > > my first message came back to me after all. here it
> > > > > > is:
> > > > > >
> > > > > > thanks for starting this group, the 707 is the center
> > > > > > of my
> > > > > > operation. i will post info and instructions about
> > > > > > mods as i do them.
> > > > > >
> > > > > > as for the mc64, cool idea. i can't help you out
> > > > > > though, in fact i
> > > > > > tore the whole slot out of mine to make room for some
> > > > > > big switches to
> > > > > > switch between the sounds of the 707 and 727. i'm
> > > > > > planning to use
> > > > > > switches from those big printer switcher boxes that
> > > > > > switch between
> > > > > > serial ports that have 25 pins. the voice roms for the
> > > > > > 707/27 have 28
> > > > > > pins. my plan is to put sockets where the voice roms
> > > > > > are, then put
> > > > > > the voice roms on a separate circuit board (with
> > > > > > sockets), hook up +
> > > > > > and gnd and pin 22 (called chip select) to the
> > > > > > positions on the
> > > > > > original board, then hook the remaining 25 pins to the
> > > > > > 25 wires
> > > > > > coming from one of the positions of the switch, and
> > > > > > the two voice
> > > > > > roms on the new board to the other 2 positions. i'm
> > > > > > thinking maybe
> > > > > > the easiest way to do the hookup is to find the right
> > > > > > size ribbon to
> > > > > > go between the sockets and the new board with the roms
> > > > > > and switches.
> > > > > > any opinions i'll definitely post my findings.
> > > > > >
> > > > > > other ideas:
> > > > > > 1. since i have the decay mods and vca inputs, i'm
> > > > > > thinking of also
> > > > > > adding some kind of cv input or internal oscillator
> > > > > > for amplitude
> > > > > > modulation of the cymbal/hh/external sounds.
> > > > > >
> > > > > > 2. 808 oscillators. the 808 hihat, cymbal, and cowbell
> > > > > > sounds are
> > > > > > generated by a hex schmitt trigger chip that is wired
> > > > > > as 6 squarewave
> > > > > > oscillators, which are mixed with resistors and then
> > > > > > filtered. my
> > > > > > idea is to at least build the oscillator section (chip
> > > > > > and a few
> > > > > > resistors and capacitors) and see how it sounds, then
> > > > > > maybe some
> > > > > > simple bandpass filters with frequency knobs. then
> > > > > > i'll plug them
> > > > > > into my vca inputs so i've got 808hh/707hh,
> > > > > > 808cy/707ride, and
> > > > > > 808cowbell/707crash! the cool thing too is that you
> > > > > > can tune the
> > > > > > pitch of the oscillators by varying the power with a
> > > > > > pot (5v max!). i
> > > > > > don't know if this has any relevance for anyone
> > > > > > because you need the
> > > > > > decay/vca mod for this to be useful, but if you
> > > > > > haven't done it i
> > > > > > highly recommend it. i'll upload plutonique9's
> > > > > > instructions from
> > > > > > Analogue Heaven, as well as the 808 schematics. the
> > > > > > modern day
> > > > > > equivalent of the chip in the 808 is call 74hc14 hex
> > > > > > schmitt trigger.
> > > > > >
> > > > > > 3. multiple trigger outs. this one i haven't quite
> > > > > > figured out. i
> > > > > > currently use the rimshot trigger to sequence an
> > > > > > analog bass drum. i
> > > > > > have a few other devices and 4 or 5 more trigger outs
> > > > > > would be
> > > > > > extremely useful! i have found the internal triggers
> > > > > > in the 707, but
> > > > > > they seem really low amplitude and maybe even negative
> > > > > > going. i
> > > > > > imagine this sort of thing can be done with a
> > > > > > comparator otherwise,
> > > > > > i'm going to try with a 555 configured as a fast
> > > > > > one-shot. again,
> > > > > > i'll post info when i try it out.
> > > > > >
> > > > > > greg
> > > > > >
> > > > > >
> > > > > > __________________________________
> > > > > > Do you Yahoo!
> > > > > > Yahoo! Finance: Get your refund fast by filing online.
> > > > > > http://taxes.yahoo.com/filing.html